A camera module to be mounted on a mobile phone, a digital camera and the like is composed of components, such as a barrel (a part in which lenses are placed), a holder (a part where the barrel is attached or supported) and the like. Recently, some camera module components have been manufactured by a liquid crystalline resin composition superior to heat resistance, mechanical properties and dimension accuracy, and capable of thin-wall molding.
By the way, in assembling steps of a camera module, a powder of a resin composition may fall from the surface of a component when assembling the component. Such a powder causes image defects if it is dropped on a CMOS sensor. In the case of a component made of a liquid crystalline resin, a phenomenon called fibrillation is one cause of the falling. This is the phenomenon in which fuzzing is generated on the surface of the component due to ultrasonic washing of the camera module component.
So far, a technique to suppress fibrillation due to ultrasonic washing has been studied, and for example, the following Patent Literature 1 proposes a liquid crystalline resin composition for injection molding, which contains silica having an average primary particle size of 5 μm or less.